Sound amplifier



April 1, 1930. F. c. HINCKLEY 1,752,526

SOUND AMPLIFIER Filed July 3, 1926 2 Sheets-Sheet 1 INVEN TOR.

F. C. HINCKLEY April 1, 1930.

SOUND AMPLIFIER Filed July 3, 1926 2 Sheets-Sheet 2 INVENTOR. inc/filePatented Apr. 1, 1930 UNITED STATES PATENT OFFIC FRANK C. HINCKLEY, OFSTRATFOIR-D, CONNECTICUT, ASSIGNGR TO COLUMBIA PHONO- GRAPH COMPANY,INC, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF NEW YORK SOUNDAMPLIFIER Application filed July 3,

This invention relates to new and useful improvements in means andmethod of amplifying sound, and has particular reference to such meansand methods when applied to I sound reproducing machines, such asphonographs or talking machines, loud speaking telephones and radioapparatus.

An object of the invention is to provide an mplifier which properlyamplifies the higher frequencies, and also amplifies and makes fullerthe base or lower frequencies.

Another object of the invention is to provide an amplifier having a pairof tone chambers, one of which is larger than the other, the sound whichpasses through the two chambers having the same point of origin butbeing divided before it reaches the chambers.

An additional object is to provide an amplifier, wherein the sound isdivided after entering the amplifier, passed through a pair of horns ofequal size into tone chambers of diiferent size, the sound beingmaintained in its divided state during its passage through the horns andtone chambers.

A further object is to provide an amplifier, including a pair of tonechambers, a pair of horns disposed one above the other and emptying intothe tone chambers, together with means disposed between the horns fordividing the sound and discharging it into the horns, the means beingsupported by the lower horn and in turn supporting the upper horn.

Additional objects and advantages will become apparent from aconsideration of the following description taken in connection with theaccompanying drawings wherein:

Fig. 1 is a front elevation of the amplifier, the same being shown asdisposed within a cabinet, the upper portion of which is broken awa v 2is a sectional view on the line 2-2 of Fig. 3;

Fig. 3 is a horizontal sectional view along the line 33 of Fig. 1 andFig. 4 is a detailed sectional view on the line l4 of Fig. 3.

Referring in detail to the drawings,-5 indicates an enclosure for theamplifier, which enclosure is shown as a phonograph cabinet,

1926. Serial No. 120,438.

certain portions thereof forming parts of the amplifier. However, itwill be understood that the amplifier may be made up as a unit andmerely slipped into the cabinet or other enclosure, and secured therein.

The am Jlifier per se includes diagonally disposed upper and lower horns6 and 7 respectively, similar in construction and size. fihese hornscomprise outside blocks 8 (see Fig. 2) having their inner surfacescurved, and inside blocks 9 having their corresponding surfaces outalong a curved line. Sides 10 connect the blocks 8 and 9 so as toprovide a complete horn having an entrance at 11 and an exit at 12.Also, these sides support the blocks in their proper relative positions.

A dividing board or partition 13 is arranged within the enclosure orcabinet 5, above the center thereof, so as to provide a pair of tonechambers 14 and 15, the chamber 1.5 being considerably larger than thechamber let. Arranged beneath, and spaced slightly from the partition 13is a member 16 for dividing the sound being amplified into two columns,one of which is passed through the upper horn 6, and the other of whichis passed through the lower horn 7.

The upper tone chamber 14 is formed by the outer wall 10 of the upperdiagonal horn and by the wall 5 of the cabinet or enclosure 5, togetherwiththe partition 13 and the upper wall 5 of the cabinet. Similarly, thelower tone chamber is formed by the outer wall 10 of the lower diagonalhorn and by the wall 5 of the cabinet together with the partition 13 andbottom 5.

Sound to be amplified is delivered into a metallic throat or conduit 17from which it passes downwardly and enters the member 16 a 18, fromwhence it is directed forwardly through the throat 19 of said member.The sound is then divided and passed through arms 20 and 21 of saidmember. That portion of the sound which passes through the arm 21 isdelivered into the upper horn 6, while the sound which has passedthrough the arm 20 is directed downwardly through opening 22 into thelower horn 7 From horns 6 and 7, th sound passes into the tone chambers14% and 15 respectively to be further amplified show and mellowed andthen discharged into the atmosphere.

Since the sound enters the diagonally disposed horns 6 and 7 towards thefront of the cabinet and is discharged therefrom at the opposite rearcorners of the cabinet, reflecting means or boards 23 are provided todirect the sound forwardly and out through the tone chambers 14 and 15.These reflectors, as n, comprise relatively thick pieces of wood havingtheir front surfaces convex. Also, the forward side board 10 of each ofthe horns is cut away at the discharge endsot the horns, as shown at 24.To prevent leakage of sound around the forward ends of the diagonallydisposed horns, curved pieces or fillers 525 are used.

As above stated, the member 16 is disposed beneath and spaced slightlyfrom the dividing board or'partition 13, and this is clearly shown inFig. 4c. In said figure, sideboards 10 shown passing through thepartition 13 and resting on the upper surface of the arm 21 of themember 16; the block 9 of the horn 6 also resting on this arm. If it isfound desirable, a filling of wax or the like can be used to close thespace between the partition and the upper portion of the lower horn andthe member 16. In actual practice, space 26 is quite small, being notmore than or '1 he upper and lower tone chambers 14 and 15 being ofdifferent size. provide for the amplification of high or shrill notes,and low or bass notes, with equal fidelity. Moreover, the partitionbeing arranged above the member 16 said member is substantiallyconcealed, its arm 20 being entirely concealed in the rear of the frontboard 10 of the lower horn while its arm 21 is concealed from casualobserva tion by the partition.

lVhais claimed is:

1. In a sound amplifier means for dividing the sound, a horn at eachside of said means and receiving the sound therefrom, said horns beingof the same size and tapering from their entrance to their exitopenings, and a pair of tonechambers receiving the sound from saidhorns, the lower of said tone chambers having a cubic capacity ofapproximately 25% more than the upper tone cha1n-.

her.

A sound amplifier comprising an entrance throat, a member receivingsound from said throat, said member dividing the sound into two columns,upper and lower horns receiving the sound from said member, a dividingboard disposed above the lower of said horns and spaced above saidmember and embracing the lower portion of the upper horn, said upperhorn resting on said memher, and a pair of tone chambers One above andthe oth r below said dividing board into which the respective hornsdischarge.

3. A sound amplifier including a compartment, a partition dividing thecompartment into which the respective horns discharge.

into a pair of tone chambers, a member disposed in one of said chambersand having a passage therethrough, including an inlet and a pair ofoutlets, a diagonally disposed horn positoned in each of saic chambersand arranged at right angles to each other, and said horns receivingsound from the outlets of said member and delivering it to said tonechambers.

i. A sound amplifier comprising. an enitrance throat, a member receivingsoundfrom said throat and dividing it into twocolumns, a pair of hornsone for each of said columns and receiving sound from said member, adividing board spaced-from one of said horns and said member andembracing the other of saidhorns, said last-mentioned horn abutting saidmember, and a pair of tone chambers one at each side of" said dividingboard and 5. In a sound amplifier, means for dividing the sound, saidmeans including a pair of diverging passages each leading to a separateexit opening, said exit openings facing opposite directions, a horn ateach of said openings and receiving the sound therefrom,-said hornsbeing of the same size and tapering from their entrance to their exitvopenings, and a pair of tone chambers receiving the sound from saidhorns, said tone chambers being ditl'erent in size and the lower of saidtone chambers having a cubic capacity approximately 25% greater than thecubic capacity of the upper tone chamber.

6. A sound amplifier comprising an en- (7 trance throat, a memberreceiving sound from said throat and dividing it into two columns, apair of horns one for each of said columns and receiving sound from saidmember, a dividing board spaced from one of said horns and said memberand embracing the other of said horns, said last-mentioned horn abuttingsaid member, a pair of tone chambers the exit portion of the lower ofsaid tone chambers being of greater cross-sectional area than the exitportion of the upper of said tone chambers,and said tone chambersdisposed one at each side of said dividing board and into which therespective horns discharge.

7. A sound amplifier comprising an eni trance throat, a member receivingsound from said throat and dividing it into two columns,

'a pair of horns one for each of said columns,

dividing means with diverging v passages emptying into said horns andwhich carry the sound in substantially opposite directions but indifferent vertical planes, and tone'chambers receiving the sound fromsaid horns and directing the same backwardly in the direction of itspassage through the dividing means.

8. A sound amplifier comprising an entrance throat, a member receivingsound from said throat and dividing it into two columns,

a pair of horns one for each of said columns, 1 30 said dividing meanshaving diverging passages emptying into said horns, said horns carryingthe sound in substantially the opposite direction but in differentvertical planes, tone chambers receiving the sound from said horns anddirecting the sound back in the direction of its passage through thedividing means, and one of said horns and tone chambers being arrangedover the other horn and tone chamber, and one horn and tone chamberdirecting sound in substantially different directions.

9. A sound amplifier comprising an entrance throat, a member receivingsound form said throat and dividing the sound into two columns, upperand lower horns receiving the sound from the respective passages in saidmember, a dividing board disposed above the lower of said horns andspaced above said member and embracing the lower portion of the upperhorn, and a pair of tone chambers one above and the other below saiddividing board into which the respective horns discharge.

Signed at Bridgeport, in the county of Fairfield, and State ofConnecticut, this 30th day of June, A. D. 1926.

FRANK O. HINCKLEY.

